<<<<<<<<<<< Click on style of louver at left to get data sheets Q. Do you have submittal sheets and free area charts? A. Yes, Click on the style of louver on the left side of this page, then click on view. (example: click on 4" Front Flange Louvers) Q. I want a custom powder coat color match. Is it
expensive? A. It can be if you need an exact match. The powder coater
needs to buy a minimum order of a $800-$1000 box of powder. If you can live with
a close match, our powder coater has been in business many years and likely
already has a color that is very close to your color. The easiest way is to look
at a RAL color chart by Google searching "RAL color chart" and click on
the images tab and tell us the RAL color number you want. (other reference: www.ralcolor.com ) In stock standard cost color
pricing is as follows:
Up to 10 sqft - $145 Flat Charge (sqft=width in ft times height in ft) 10-25 sqft - $235 Flat Charge for multiple louvers of same color adding up to 25 sqft 26-199 sqft - $8.75 per sqft 200-299 sqft - $8.00 per sqft 300 sqft and up - $7.00 per sqft Q. Do you have suggestions on installation? A. Typically one could use #10x1-1/2" Stainless Steel screws for wood or 1/4"x2-3/8" concrete screws for stucco (eg Tapcon Hex Head). Be sure to use the vertical flanges to support most of the weight of the louver since they are directly attached to the blades. Do not support the louver only by the top and bottom flanges, you must also use the vertical flanges. Don't go more than 16" between screw locations. Use a good quality caulk around the louver to prevent rain water running down the wall to behind the louver flange. It would also be good practice to place caulk on the exterior bottom seams of the louver before inserting into the wall to prevent water leaks. Click on: Installation on left side of this page Q. What is your email address?
Q. How many vents do I need for my attic?
A. The general rule of thumb for a typical louver on the amount of
total attic vent space needed is approximately 1 sq. ft. of vent space for every
150 sq. ft. of attic area. Ideally, half the vents should be located in the
soffit at the bottom of the roof and half in vents near the top to allow for
natural circulation of air through the attic. Multiply the length of the attic
times the width in feet to find the total square feet of the attic, then divide
by 150 [(length x width of attic in feet) ÷ 150 = total sq. ft. vent
area] Example: a 50′ x 30′ attic would have a total area of 1,500 sq. ft.,
divided by 150 equals 10 sq. ft. of total vent space needed. Divide the total
vent area by two to divide equally the soffit vent area and the upper gable vent
area. Q. Can you help me understand air flow and louver size calculations? A. Lets start with the volume of air in a room. Lets say you have a shop room that is 40 ft x 30 ft with 20 ft high ceiling. The volume of air in the room would be 40x30x20 = 24,000 cubic ft. Lets say we want to change the air in the room 3 times per hour, so 24,000 x 3 = 72000 cubic ft would need to be moved in one hour. Most fans are rated in cubic ft per minute so 72000 divided by 60 min/hr = 1200 cubic ft per minute or 1200 cfm. So you would need to buy fans that have cfm ratings that add up close to 1200 cfm. If you already have fans, use their cfm for further calculations. Now to figure what size louver is needed, we will use the formula of cfm=velocity x area. The volume of air per minute equals the speed of air in ft per minute (fpm) times the free area of air that gets though the louver. Let say we know from our example the cfm is 1200 cfm. We now need to choose how fast we want the air to flow. Some recommended velocities for air intake and exhaust for exterior applications are from 500 - 700 fpm. For interior, recommendations are from 200 - 400 fpm for low noise and low pressure drop. Louvers have blades and a frame that partially block the air. There are charts that display the unrestricted Free Area of different size louvers (see top of this page for Free Area Data sheets). Lets say we want to use 500 fpm for our shop room air movement. So cfm=fpm x sqft or 1200 cfm = 500 fpm x sqft free area. So free area sqft = 1200 / 500 = 2.4 sqft. We now can look at the free area charts to see which sizes of louver(s) add up to 2.4 sqft. As a starting point, we can guess at using a 2 ft wide louver and guess at it having a 50% free area, so 2.4 sqft free area needed divided by .50 = 4.8 sqft size of louver, so 4.8sqft divided by 2ft wide gives us 2.4 ft high. a 2ft wide x 2.4 ft high louver is the same as 24" wide x a little less than 29" high. Now look at the chart and get the actual free area and redo the calculation for that size and other sizes that are more appealing for your application. Another example: Louver size is 2" depth x 48"x48". Looking at the Free Area chart, it shows a Free Area of 8.96 sqft. If the opening for the louver is 4'x4', the opening would be 4x4=16sqft. If we take the Free Area of 8.96 and divided by 16, we would see that louver would allow roughly 8.96/16=56% of the air through. To see how much cfm capacity the louver has, you need to know the speed of the air you want. Rule of thumb is don't exceed 725 fpm on intake louvers, so if we use 725 fpm, then Free Area 8.96 times speed of air of 725 = 6496 cfm maximum fan volume per 48"x48" louver. Go Back to: www.planbmfg.com: |